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Histone acetylation modifications in filamentous fungi play a crucial role in epigenetic gene regulation and are closely linked to the transcription of secondary metabolite (SM) biosynthetic gene clusters (BGCs). Histone deacetylases (HDACs) play a pivotal role in determining the extent of histone acetylation modifications and act as triggers for the expression activity of target BGCs. The genus Chaetomium is widely recognized as a rich source of novel and bioactive SMs. Deletion of a class I HDAC gene of Chaetomium olivaceum SD-80A, g7489, induces a substantial pleiotropic effect on the expression of SM BGCs. The C. olivaceum SD-80A ∆g7489 strain exhibited significant changes in morphology, sporulation ability, and secondary metabolic profile, resulting in the emergence of new compound peaks. Notably, three polyketides (A1–A3) and one asterriquinone (A4) were isolated from this mutant strain. Furthermore, our study explored the BGCs of A1–A4, confirming the function of two polyketide synthases (PKSs). Collectively, our findings highlight the promising potential of molecular epigenetic approaches for the elucidation of novel active compounds and their biosynthetic elements in Chaetomium species. This finding holds great significance for the exploration and utilization of Chaetomium resources. Key points: • Deletion of a class I histone deacetylase activated secondary metabolite gene clusters. • Three polyketides and one asterriquinone were isolated from HDAC deleted strain. • Two different PKSs were reported in C. olivaceum SD-80A. [ABSTRACT FROM AUTHOR]

The association of endophytic fungi with plants was recorded from an early stage of evolution. Endophytic fungi of medicinally important plants are given importance as they mimic the synthesis of bioactive compounds by the host plant. Chromolaena odorata is a wild medicinal plant used in ethnomedicine by different communities. From the root part of C. odorata, an endophytic fungus, Chaetomium sp. R1C1, was isolated, and its biological activities were evaluated. The ITS-rDNA gene sequencing of Chaetomium sp. R1C1 showed 99.21% similarity with Chaetomium globosum. Chaetomium sp. R1C1 was found to secrete protease, amylase, lipase, and cellulose and also produce ammonia. The isolate shows strong antifungal activities against all the nine tested phytopathogens, with the highest inhibition against U. virens (97.45%), followed by A. flavus (94.70%), C. lunata (89.09%), A. brassicicola (78.41%), F. oxysporum (77.71%), R. solani (70.27%), C. capsici (64.41%), A. niger (57.06%), and A. alternata (45.35%). The antibacterial activity evaluated using the agar-well diffusion method and 96-well microtitre method shows that the crude extract was more efficient against gram-negative bacteria, with the highest activity against S. typhi. The DPPH radical scavenging activity shows inhibition of 60.18% and an IC50 value of 85.88 µg/mL, which makes it a strong antioxidant. GC-MS and LC-MS are powerful tools employed to reveal the compounds present in the secondary metabolite of Chaetomium sp. R1C1. This study highlights the importance and applications of the endophytic fungus Chaetomium sp. R1C1 in the fields of agriculture, medicine, and industries. [ABSTRACT FROM AUTHOR]

Biological methods present a sustainable approach for treating various waste polymers due to green, low-cost, mild condition and simple operation. This study, a novel biological method to process nitrocellulose (NC) to obtain NC with low nitrogen via nitrate ester removal using fungal Chaetomium elatum is proposed. The N% of NC continuously declined during the course of six days, from 13.06% to 11.71%, and the intensity of its energetic groups (O-NO2, -NO2) also weakened. An examination of the thermal properties of NC revealed that the weight-loss ratio decreased after biotreatment from 86.33% (untreated NC) to 66.20% (treated NC).Furthermore, the kinetic parameters of the thermal decomposition reaction with DSC were calculated and the activation energy (Ea) of biotreated NC was higher than that of the original, indicating the thermal stability was enhanced. Hence, this structure exploration and thermal analysis provide new methods for further investigating the mechanism of the biological denitrification process and assessing the safety of biotreated NC. [ABSTRACT FROM AUTHOR]

This article, published in Chemistry of Natural Compounds, discusses the secondary metabolites of Chaetomium angustispirale, a fungus with over 400 species. The study focuses on the extraction and isolation of compounds from the fermented extract of C. angustispirale. Six compounds were identified, including orsellinic acid, orsellide A, shanorellin, adenosine, cochliodinol, and ergosterol. These compounds have novel chemical structures and exhibit significant biological activities, making them valuable resources for drug development. The research was funded by various organizations in Henan Province, China. [Extracted from the article]

Background: Endophytic fungi have proven to be a rich source of novel natural products with a wide-array of biological activities and higher levels of structural diversity. Results: Chemical investigation on the liquid- and solid-state fermented products of Chaetomium globosum Km1226 isolated from the littoral medicinal herb Atriplex maximowicziana Makino resulted in the isolation of compounds 1–14. Their structures were determined by spectroscopic analysis as three previously undescribed C13-polyketides, namely aureonitol C (1), mollipilins G (2), and H (3), along with eleven known compounds 4–14. Among these, mollipilin A (5) exhibited significant nitric oxide production inhibitory activity in LPS-induced BV-2 microglial cells with an IC50 value of 0.7 ± 0.1 µM, and chaetoglobosin D (10) displayed potent anti-angiogenesis property in human endothelial progenitor cells (EPCs) with an IC50 value of 0.8 ± 0.3 µM. Conclusions: Three previously unreported compounds 1–3 were isolated and identified. Mollipilin A (5) and chaetoglobosin D (10) could possibly be developed as anti-inflammatory and anti-angiogenic lead drugs, respectively. [ABSTRACT FROM AUTHOR]

The eukaryotic guided entry of tail-anchored proteins (GET) pathway mediates the biogenesis of tail-anchored (TA) membrane proteins at the endoplasmic reticulum. In the cytosol, the Get3 chaperone captures the TA protein substrate and delivers it to the Get1/Get2 membrane protein complex (GET insertase), which then inserts the substrate via a membrane-embedded hydrophilic groove. Here, we present structures, atomistic simulations and functional data of human and Chaetomium thermophilum Get1/Get2/Get3. The core fold of the GET insertase is conserved throughout eukaryotes, whilst thinning of the lipid bilayer occurs in the vicinity of the hydrophilic groove to presumably lower the energetic barrier of membrane insertion. We show that the gating interaction between Get2 helix α3' and Get3 drives conformational changes in both Get3 and the Get1/Get2 membrane heterotetramer. Thus, we provide a framework to understand the conformational plasticity of the GET insertase and how it remodels its membrane environment to promote substrate insertion. Tail-anchored (TA) membrane protein biogenesis is mediated by the GET insertase. Here, authors present cryo-EM and X-ray structures, MD simulations and functional data for human and fungal insertases showing membrane remodeling for TA insertion. [ABSTRACT FROM AUTHOR]

Chaetomium globosum Kunze, an internationally recognized biocontrol fungus. It mycoparasitizes various plant pathogens and produce antifungal metabolites to suppress the growth of pathogenic fungi. Lack of detailed genome level diversity studies has delimited the development and utilization of potential C. globosum strains. The present study was taken to reveal the distribution, identification, and characterization of expressed sequence tag-simple sequence repeats (EST-SSRs) in C. globosum. RNA-Seq experiment was performed for C. globosum potential isolate Cg2 (AY429049) using Illumina HiSeq 2500. Reference-guided de novo assembly yielded 45,582 transcripts containing 27,957 unigenes. We generated a new set of 8485 EST-SSR markers distributed in 5908 unigene sequences with one SSR locus distribution density per 6.1 kb. Six distinct classes of SSR repeat motifs were identified. The most abundant were mononucleotide repeats (51.67%), followed by tri-nucleotides (36.61%). Out of 5034 EST-SSR primers, 50 primer pairs were selected and validated for the polymorphic study of 15 C. globosum isolates. Twenty-two SSR markers showed average genetic polymorphism among C. globosum isolates. The number of alleles (Na) per marker ranges from 2 to 4, with a total of 74 alleles detected for 22 markers with a mean polymorphism information content (PIC) value of 0.4. UPGMA hierarchical clustering analysis generated three main clusters of C. globosum isolates and exhibited a lower similarity index range from 0.59 to 0.85. Thus, the newly developed EST-SSR markers could replace traditional methods for determining diversity. The study will also enhance the genomic research in C. globosum to explore its biocontrol potential against phytopathogens. [ABSTRACT FROM AUTHOR]

Interest in cave fungal diversity is flourishing because it may represent a reservoir of new species and metabolites. However, the mycobiota remains poorly studied in the underground environment, especially in neotropical regions. During surveys that aimed to investigate the fungal diversity in quartzite and limestone caves in the Southern Espinhaço Mountain in Brazil, six Chaetomiaceae isolates were obtained from different cave substrates. Five taxonomical novelties of Chaetomiaceae in Brazilian caves were discovered based on phylogenetic analyses using DNA sequences from the ITS, LSU, TUB, and RPB2 genes. Chaetomium meridionalense, Pseudohumicola alba, and Pseudohumicola lutea are new species found in Gruta da Extração and Gruta Velha Nova caves. Parahumicola is introduced as a new genus representing a novel phylogenetic lineage with unique morphological characteristics in the family Chaetomiaceae. This new monotypic genus is typified by P. guana, which was found in a bat guano sample in the Gruta Monte Cristo cave. Furthermore, this is the first report of Collariella bostrychodes in a neotropical cave. Overall, these findings emphasise that Brazilian caves constitute an untapped source of fungal resources. [ABSTRACT FROM AUTHOR]

The oxoglutarate dehydrogenase complex (OGDHc) participates in the tricarboxylic acid cycle and, in a multi-step reaction, decarboxylates α-ketoglutarate, transfers succinyl to CoA, and reduces NAD+. Due to its pivotal role in metabolism, OGDHc enzymatic components have been studied in isolation; however, their interactions within the endogenous OGDHc remain elusive. Here, we discern the organization of a thermophilic, eukaryotic, native OGDHc in its active state. By combining biochemical, biophysical, and bioinformatic methods, we resolve its composition, 3D architecture, and molecular function at 3.35 Å resolution. We further report the high-resolution cryo-EM structure of the OGDHc core (E2o), which displays various structural adaptations. These include hydrogen bonding patterns confining interactions of OGDHc participating enzymes (E1o-E2o-E3), electrostatic tunneling that drives inter-subunit communication, and the presence of a flexible subunit (E3BPo), connecting E2o and E3. This multi-scale analysis of a succinyl-CoA-producing native cell extract provides a blueprint for structure-function studies of complex mixtures of medical and biotechnological value. Summary: Multi-scale and integrative structural analyses provide insight into metabolic regulation by the higher-order architecture of the Chaetomium thermophilum oxoglutarate dehydrogenase complex (OGDHc) metabolon. [ABSTRACT FROM AUTHOR]

Endophytic fungi have proved to be a major source of secondary metabolites, wherein the genus Chaetomium has emerged as a source of multifarious bioactive natural compounds belonging to diverse classes such as chaetoglobosins, epipolythiodioxopiperazines, azaphilones, xanthones, anthraquinone, chromones, depsidones, terpenoids, and steroids. The objective of this review is to encapsulate recent findings on various Chaetomium strains, such as C. globosum, C. cupreum, C. elatum, C. subspirale, C. olivaceum, C. indicum, and C. nigricolor known for production of beneficial secondary metabolites, with an insight into their origin and function. A thorough literature survey was conducted for obtaining Chaetomium-derived secondary metabolites, with a scope of future application into drug development efforts. More than 100 secondary metabolites, with various beneficial properties such as antitumor, cytotoxic, antimalarial, and enzyme inhibitory activities, were enlisted. We believe this review will enhance the understanding of beneficial effects conferred by various Chaetomium-derived secondary metabolites and emphasize their potential in serving novel drug development efforts. Key points: • IdentifiedChaetomium-derived metabolites with potential for drug development. • More than 100 beneficial metabolites are enlisted. • Benefits include anti-cancerous, antimalarial, and anti-enzymatic properties. [ABSTRACT FROM AUTHOR]

The antimicrobial activity of endophytic fungi isolated from Euphorbia milii was evaluated against Gram-positive, Gram-negative bacteria, unicellular yeast, and filamentous fungi. Chaetomium ovatoascomatis NRC was identified morphologically and genetically as the most active strain. The total ethyl acetate extract of C. ovatoascomatis NRC demonstrated significant antimicrobial activity against Gram-negative; Escherichia coli, Salmonella enteric, and fungi; Aspergillus niger with MIC of 62.5 ug/ml. Whereas n-hexane fraction demonstrated broader activity against Gram-positive; Bacillus subtilis, Lactobacillus cereus, Gram-negative; Escherichia coli and Salmonella enteric, fungi; Candida albicans and F. solani. LC–MS/MS analysis of ethyl acetate strain extract and GC–MS analysis of the n-hexane fraction were used to identify the metabolites of the strain extract. LC–MS/MS determined three major metabolites with potential antimicrobial activities including grevilline B, aflatoxin G2 and apigenin. GC–MS analysis of n-hexane fraction tentatively identified 30 compounds, where 9,12-octadecadienoic acid methyl ester was the major compound. [ABSTRACT FROM AUTHOR]

Late wilt is a soil-borne disease caused by Cephalosporium maydis that severely limits maize production. In this study, endophytic Chaetomium isolates were screened for their abilities to control C. maydis on agar plates. In a dual culture test, Chaetomium spp. isolate Ch-1 inhibited 91.0% mycelial growth of C. maydis. The pathogen's mycelial growth and conidial germination were also inhibited by its crude extracts. This isolate was identified as C. globosum (Chg-1) based on sequencing of the internal transcribed spacer regions of the rRNA gene. There are three Chg-1 application methods viz. grain treatment GT, soil application SA either individually or in combination GT + SA and two maize cultivars viz. landraces and fine seed 1005 were applied in pots and field plot experiments in controlling late wilt disease. In pots, Chg-1 treatments significantly reduced late wilt disease incidence and increased plant growth of the two maize cultivars, with a high efficacy for GT + SA compared to the positive control. Despite minor differences, treatments GT and SA provided adequate protection against late wilt. After 90 days of cultivation, the endophyte Chg-1 was re-isolated from the internodes of treated maize plants without causing any symptoms. This endophytic fungus reduced late wilt incidence in pots not only directly by antagonizing the pathogen, but also indirectly by inducing resistance mechanisms in maize plants. The induction of antioxidant enzymes (including peroxidase and polyphenoloxidase), chitinase, chlorophyll content, total phenols, and flavonoids was responsible for the indirect effects of Chg-1 against the pathogen. In the field, the endophyte not only reduced late wilt symptoms but also increased ear yield on both maize cultivars when compared to the untreated control. A combination of soil application and grain treatment with Chg-1 (GT + SA) outperformed any of these treatments individually in terms of reducing late wilt incidence and increasing grain yield in maize. [ABSTRACT FROM AUTHOR]

Graph The EtOAc extracts were fractionated by column chromatography with silica gel, Sephadex LH-20, and preparative HPLC to afford compounds B 1 b - B 7 b . These compounds were determined to be chaetoviridin A ( B 1 b ) [[6]], chaetoviridin B ( B 2 b ) [[6]], chaetomugilin I ( B 3 b ) [[8]], chaetomugilin A ( B 4 b ) [[9]], 11-epichaetomugilin A ( B 5 b ) [[10]], chaetoglobosin R ( B 6 b ) [[11]], and 10,11-dihydroxyaureonitol ( B 7 b ) [[12]] by comparing their 1D NMR and ESI-MS data with the literature. Compound B 3 b exhibited significant antitumor activities against PC9, TE-1, KYSE-30, SW-620, and MDA-MB-231 cell lines (Table 1). The isolated compounds B 1 b - B 5 b belong to azaphilones, which have various bioactivities, such as cytotoxic, antimicrobial, and nitric oxide inhibitory activities [[13]-[15]]. [Extracted from the article]

Chaetomium fungi produce a diversity of bioactive compounds. Chaetomium cochliodes SD-280 possesses 91 secondary metabolite gene clusters and exhibits strong antibacterial activity. One of the active compounds responsible for that activity, chetomin, has a minimum inhibitory concentration (MIC) for anti-methicillin-resistant Staphylococcus aureus (MRSA) of 0.05 μg/mL (vancomycin: 0.625 μg/mL). This study demonstrated that the addition of glutathione (GSH) can enhance chetomin yield dramatically, increasing its production 15.43-fold. Following genome sequencing, cluster prediction, and transcriptome and proteome analyses of the fungus were carried out. Furthermore, a relatively complete chetomin biosynthetic gene cluster was proposed, and the coding sequences were acquired. In the cluster of GSH-treated cells, proteome analysis revealed two up-regulated proteins that are critical enzymes for chetomin biosynthesis. One of these enzymes, a nonribosomal peptide synthetase (NRPS), was heterologously expressed in Aspergillus nidulans, and one of its metabolites was determined to be an intermediate in the chetomin biosynthetic pathway. We present here, to our knowledge, the first experimental evidence that chetomin exhibits strong bioactivity against MRSA. Our work also provides extensive insights into the biosynthetic pathway of chetomin, in particular identifying two key enzymes (glutathione S-transferase (CheG) and NRPS (CheP)) that substantially up-regulate chetomin. These mechanistic insights into chetomin biosynthesis will provide the foundation for further investigation into the anti-pathogenic properties and applications of chetomin. Key points: • Chetomin exhibits strong anti-MRSA activity with MIC of 0.05 μg/mL. • Addition of glutathione improved the yield of chetomin by 15.43-fold. • CheG and CheP involved in the chetomin biosynthesis were revealed for the first time. [ABSTRACT FROM AUTHOR]

Black scurf in potatoes is caused by the pathogenic fungus Rhizoctonia (R.) solani, and is a serious disease that results in both quantitative and qualitative losses in potato yields worldwide. To manage this disease in an eco-friendly manner, isotonic aqueous formulation of Chaetomium (C.) globosum was developed and tested for disease control efficacy under both glasshouse and field conditions. A total of 40 fungal isolates was tested in vitro, among which C. globosum Cg-6 exhibited maximum inhibition potential of R. solani (60%) and an increased vigor index (1960.0) in potatoes assessed by the roll towel method. The isotonic solution amended with glycerol supported a maximum fungal population (1.9 × 107 cfu per ml) up to 6 months and retained the most antagonistic activity compared to other preservatives tested (glycine, trehalose, and polyvinylpyrrolidone). Results showed that combined application of C. globosum Cg-6 as a tuber treatment, soil application, and foliar spray effectively reduced the incidence of black scurf (7.6%) and enhanced the germination (94%) of tuber under glasshouse conditions. During field trials, a treatment consisting of C. globosum (TNAU Cg-6; 5 ml per kg of seed), soil application (5 ml per kg of farm-yard manure), and foliar application of 5 ml per litre of water (6 sprays), was shown to reduce black scurf in potatoes and enhanced tuber yield. [ABSTRACT FROM AUTHOR]

Found across all kingdoms of life, 2-keto acid dehydrogenase complexes possess prominent metabolic roles and form major regulatory sites. Although their component structures are known, their higher-order organization is highly heterogeneous, not only across species or tissues but also even within a single cell. Here, we report a cryo-EM structure of the fully active Chaetomium thermophilum pyruvate dehydrogenase complex (PDHc) core scaffold at 3.85 Å resolution (FSC = 0.143) from native cell extracts. By combining cryo-EM with macromolecular docking and molecular dynamics simulations, we resolve all PDHc core scaffold interfaces and dissect the residing transacetylase reaction. Electrostatics attract the lipoyl domain to the transacetylase active site and stabilize the coenzyme A, while apolar interactions position the lipoate in its binding cleft. Our results have direct implications on the structural determinants of the transacetylase reaction and the role of flexible regions in the context of the overall 10 MDa PDHc metabolon architecture. How is acetyl-CoA produced in the context of the endogenous, eukaryotic pyruvate dehydrogenase complex metabolon? Here the authors dissect the embedded transacetylase reaction through biochemical, cryo-EM, HADDOCKing and molecular dynamics methods. [ABSTRACT FROM AUTHOR]

Subfraction B2-2 was by further subjected to repeated silica gel column chromatography and semipreparative reversed-phase HPLC (H SB 2 sb O-MeOH, 2:3) to afford compounds B 1 b and B 2 b . Subfraction B2 was separated by silica gel column chromatography and eluted with petroleum ether-ethyl acetate to give compound B 6 b and B 1 b . Subfraction B2-3 was by further repeated silica gel column chromatography and semipreparative RP-HPLC (H SB 2 sb O-MeOH, 3:2) to afford compound B 1 b . The culture afforded a dark brown crude extract, which was subjected to silica gel column chromatography and eluted successively with ethyl acetate-methanol gradient to yield six fractions (A-F). [Extracted from the article]

Compound B 2 b displayed the most significant antibacterial effects on I B. subtilis i with an MIC value of 4 g/mL I . i Moreover, compounds B 3 b , B 5 b , B 7 b , and B 10 b revealed ordinary antibacterial activities against I B. subtilis i with MIC values of 32, 16, 32, and 16 g/mL, respectively. Subfraction 2.1 was further purified by silica gel CC and eluted by petroleum ether-acetone (7:3-1:1) to give compound B 1 b (11.5 mg). Fraction 3 (3.5 g) was purified by silica gel CC with petroleum ether-acetone (4:1-1:1) to obtain compounds B 3 b (15.1 mg) and B 6 b (13.0 mg). Graph The antibacterial and antifungal activities of compounds B 1 b - B 10 b were assayed by the broth microdilution process reported in detail earlier [[23]]. [Extracted from the article]

The accurate taxonomic concept of the fungal Chaetomium species has been a hard work due to morphological similarity. Chemotaxonomy based on secondary metabolites is a powerful tool for taxonomical purposes, which could be used as an auxiliary reference to solve the problems encountered in the classification of Chaetomium. Among secondary metabolites produced by Chaetomium, cytochalasans and azaphilones exhibited a pattern of distribution and frequency of occurrence that establish them as chemotaxonomic markers for the Chaetomium species. This review attempted to elucidate the composition of the Chaetomium species and its relationship with classical taxonomy by summarizing the pattern of cytochalasans and azaphilones distribution and biosynthesis in the Chaetomium species. Key points: • Secondary metabolites from the genus Chaetomium are summarized. • Cytochalasans and azaphilones could be characteristic metabolites of the Chaetomium species. • Cytochalasans and azaphilones could be used to analyze for taxonomical purposes. [ABSTRACT FROM AUTHOR]

Glycyrrhetic acid 3-O-mono-β-d-glucuronide (GAMG) as an important derivative of glycyrrhizin (GL) shows stronger biological activities and higher sweetness than GL. The biotransformation process is considered as an efficient strategy for GAMG production, due to its mild reaction, high production efficiency and environmentally friendly status. In this study, licorice straw was used for the first time as a medium for GAMG and lignocellulosic enzyme production via solid-state fermentation (SSF) of endophytic fungus Chaetomium globosum DX-THS3. The fermentation conditions including particle size, temperature, seed age, inoculum size, and moisture of substrate were optimized. Furthermore, additional nitrogen sources and carbon sources were screened for GAMG production by C. globosum DX-THS3 of SSF. Under optimal fermentation conditions, the percent conversion of glycyrrhizin reached 90% in 15 days, whereas the control needed 35 days to achieve the same result. The productivity of optimization (P = 2.1 mg/g/day) was 2.33-fold that of non-optimization (P = 0.9 mg/g/day). Meanwhile, high activities of filter paper enzyme (FPase) (245.80 U/g), carboxymethyl cellulase (CMCase) (33.67 U/g), xylanase (83.44 U/g), and β-glucuronidase activity (271.42 U/g) were obtained faster than those in the control during SSF. Our study provides a novel and efficient strategy for GAMG production and indicates C. globosum DX-THS3 as a potential producer of lignocellulolytic enzymes. [ABSTRACT FROM AUTHOR]

Genetic manipulation of Escherichia coli influences the regulation of bacterial metabolism, which could be useful for the production of different targeted products. The RpoZ gene encodes for the ω subunit of the RNA polymerase (RNAP) and is involved in the regulation of the relA gene pathway. RelA is responsible for the production of guanosine pentaphosphate (ppGpp), which is a major alarmone in the stringent response. Expression of relA is reduced in the early hours of growth of RpoZ mutant E. coli. In the absence of the ω subunit, ppGpp affinity to RNAP is decreased; thus, rpoZ gene deleted E. coli strains show a modified stringent response. We used the E. coli K-12 MG1655 strain that lacks rpoZ (JEN202) to investigate the effect of the modified stringent response on recombinant protein production. However, the absence of the ω subunit results in diminished stability of the RNA polymerase at the promoter site. To avoid this, we used a deactivated CRISPR system that targets the ω subunit to upstream of the promoter site in the expression plasmid. The expression plasmid encodes for Chaetomium thermophilum formate dehydrogenase (CtFDH), a valuable enzyme for cofactor regeneration and CO2 reduction. A higher amount of CtFDH from the soluble fraction was purified from the JEN202 strain compared to the traditional BL21(DE3) method, thus offering a new strategy for batch-based recombinant enzyme production. [ABSTRACT FROM AUTHOR]

The herbicide butachlor has been used in huge quantities worldwide, affecting various environmental systems. Butachlor residues have been detected in soil, water, and organisms, and have been shown to be toxic to these non-target organisms. This paper briefly summarizes the toxic effects of butachlor on aquatic and terrestrial animals, including humans, and proposes the necessity of its removal from the environment. Due to long-term exposure, some animals, plants, and microorganisms have developed resistance toward butachlor, indicating that the toxicity of this herbicide can be reduced. Furthermore, we can consider removing butachlor residues from the environment by using such butachlor-resistant organisms. In particular, microbial degradation methods have attracted much attention, with about 30 kinds of butachlor-degrading microorganisms have been found, such as Fusarium solani, Novosphingobium chloroacetimidivorans, Chaetomium globosum, Pseudomonas putida, Sphingomonas chloroacetimidivorans, and Rhodococcus sp. The metabolites and degradation pathways of butachlor have been investigated. In addition, enzymes associated with butachlor degradation have been identified, including CndC1 (ferredoxin), Red1 (reductase), FdX1 (ferredoxin), FdX2 (ferredoxin), Dbo (debutoxylase), and catechol 1,2 dioxygenase. However, few reviews have focused on the microbial degradation and molecular mechanisms of butachlor. This review explores the biochemical pathways and molecular mechanisms of butachlor biodegradation in depth in order to provide new ideas for repairing butachlor-contaminated environments. Key points: • Biodegradation is a powerful tool for the removal of butachlor. • Dechlorination plays a key role in the degradation of butachlor. • Possible biochemical pathways of butachlor in the environment are described. [ABSTRACT FROM AUTHOR]

Lytic polysaccharide monooxygenases (LPMOs) are auxiliary enzymes catalyzing oxidative cleavages of cellulose chains in crystalline regions, resulting in their increasing accessibility to the hydrolytic enzyme counterparts and hence higher released sugars from biomass saccharification. In this study, a novel auxiliary protein family 9 LPMO (BgAA9) was identified from a metagenomic library derived from a thermophilic microbial community in bagasse collection site where diverse AA9 and AA10 putative sequences were annotated. The enzyme showed highest similarity to a glycoside hydrolase family 61 from Chaetomium thermophilum. Recombinant BgAA9 expressed in Pichia pastoris cleaved cellohexaose (DP6) into shorter cellooligosaccharides (DP2, DP3, and DP4). Supplementation BgAA9 to a commercial cellulase, Accellerase® 1500 showed strong synergistic effect on saccharification of Avicel® PH101, decrystallized cellulose, filter paper, and alkaline-pretreated sugarcane bagasse, resulting in 63–93% increase in the total reducing sugar yield after incubation at 50 °C for 72 h. Strong synergism was shown between BgAA9 and the cellulase with the highest total fermentable sugar yield obtained from 75:25% of Accellerase®1500:BgAA9 which released 39 mg glucose/FPU (filter paper unit) equivalent to 38.7% higher than Accellerase®1500 alone at the same total protein dosage of 5 mg/g substrate according to the mixture design study. The enzyme represented the first characterized LPMO from environmental metagenome and a potent auxiliary component for biomass saccharification. Key points: • BgAA9 represents the first characterized LPMO from metagenome. • 12 AA families were annotated in thermophilic bagasse fosmid library by NGS. • BgAA9 showed homology to Cel61 in Chaetomium thermophilum. • BgAA9 oxidized cellohexaose and PASC to DP2, DP4, and DP6. • BgAA9 showed strong synergism to Accellerase on bagasse hydrolysis. [ABSTRACT FROM AUTHOR]

The study describes the development and employment of plant tests based on artificial inoculation of seeds or the potting substrate for evaluating the potential of microorganisms to control seedling blight of maize caused by seed- and soil-borne fusaria. Nine strains of Fusarium were isolated from maize kernels and identified morphologically and by molecular methods as belonging to the species Fusarium verticillioides, F. subglutinans, F. cerealis, F. poae and F. proliferatum. In order to determine pathogenicity, maize kernels were inoculated by immersion in suspensions of conidia of these isolates and sown in a pasteurized substrate in seed trays. Based on plant dry weight, the isolates of F. verticillioides and F. subglutinans were more pathogenic than the other isolates. Using an isolate of F. subglutinans, the efficacy of a set of 25 potential fungal and bacterial antagonists was assessed using inoculation of maize kernels by placement in mixtures of the pathogen and the antagonists. The results obtained with this methodology indicate the potential of a number of different microorganisms applied as seed treatments, including some reported previously as biocontrol agents, to control seed-borne seedling blight of maize. In order to develop a method for the testing of biocontrol agents against soil-borne attack, isolates of F. subglutinans, F. cerealis and F poae from maize kernels together with isolates of F. avenaceum, F. culmorum and F. graminearum originating from maize silage and wheat were used to artificially inoculate the potting substrate. The results showed large differences in pathogenicity, with the most aggressive isolates belonging to F. culmorum and F. graminearum. [ABSTRACT FROM AUTHOR]

Objectives: Formate dehydrogenases (FDHs) are NAD(P)H-dependent enzymes that catalyse the reversible oxidation of formate to CO2. The main goal was to use directed evolution to obtain variants of the FDH from Chaetomium thermophilum (CtFDH) with enhanced reduction activity in the conversion of CO2 into formic acid. Results: Four libraries were constructed targeting five residues in the active site. We identified two variants (G93H/I94Y and R259C) with enhanced reduction activity which were characterised in the presence of both aqueous CO2(g) and HCO3−. The A1 variant (G93H/I94Y) showed a 5.4-fold increase in catalytic efficiency (kcat/KM) compared to that of the wild-type for HCO3− reduction. The improved biocatalysts were also applied as a coupled cofactor recycling system in the enantioselective oxidation of 4-phenyl-2-propanol catalysed by the alcohol dehydrogenase from Streptomyces coelicolor A3 (ScADH). Conversions in these reactions increased from 56 to 91% when the A1 variant was used instead of wild-type CtFDH. Conclusions: Two variants presenting up to five-fold increase in catalytic efficiency and kcat were obtained and characterised. They constitute a promising enzymatic alternative for CO2 utilization and will serve as scaffolds to be further developed in order to meet industrial requirements. [ABSTRACT FROM AUTHOR]

The endophytic fungus Chaetomium sp. was separated from the medicinal plant Salvia officinalis growing in Egypt and cultivated on solid rice medium. Chemical investigation of the EtOAc extract yielded a new hydroperoxycochliodinol derivative (1) in addition to several known compounds, which included cochliodinol (2), isocochliodinol (3), chaetomin (4), and two simple indole derivatives (5, 6). The structure of the new compound was determined by comprehensive NMR studies including DEPT, COSY, HMQC, HMBC, and HR-MS. All compounds were tested for their cytotoxic activity against L5178Y cells. Compounds 1, 2, and 4 showed cytotoxic activity with EC50 values between 3.5–5.0 μg/mL, whereas compounds 3, 5, and 6 were inactive. [ABSTRACT FROM AUTHOR]

Increasing attention has recently been focused on complex symbiotic associations, for instance coral and its symbionts. Sea cucumber, harboring diverse fungi, has also attracted more and more attention for their functional diversity. Here, secondary metabolites produced by Chaetomium globosum associated with sea cucumber, Apostichopus japonicus, were investigated using gene mining with third-generation sequencing technology (PacBio SMRT). Nine compounds, including one new compound cytoglobosin X (1), were isolated from cultures of Chaetomium globosum. Compound 1 was identified based on NMR data, HRESIMS, and ECD, and the absolute configurations were identified as 3S, 4R, 7S, 8R, 9R, 16S, 19S, 20S, and 23S. In an antimicrobial assay, compound 4 showed moderate activity against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus with MICs of 47.3 and 94.6 μM, respectively. Our results suggest that the microbiomes associated with sea cucumber could be an important resource for biodiversity and structural novelty, and the bioactive compounds may protect the host from pathogen microbial. [ABSTRACT FROM AUTHOR]

Glycyrrhetinic acid monoglucuronide (GAMG) is a novel and low-calorie sweetener that is widely applied in the food industry. This study aimed to enhance the production of fungal β-d-glucuronidase (GUS) via a novel fermentation technique by evaluating the effects of the various microparticles on Chaetomium globosum DX-THS3 GUS production. Results showed that the silica microparticle greatly affected the morphology of DX-THS3 strain relative to the other microparticles. Microbial structure imaging results showed that the smallest average diameter of fungal pellets was achieved (0.7 ± 0.1 mm) by adding 10 g/L (600 mesh) of silica. The diameter of the control was 3.0 ± 0.5 mm in shake flask fermentation. The GUS activity and biomass of DX-THS3 reached 680 U/mL and 4.2 g/L, respectively, with the use of 10 g/L of silica microparticles, whereas those of the control were 210 U/mL and 2.8 g/L via shake flask fermentation. The findings in this study may provide a potential strategy for designing the morphology of filamentous fungi using microparticles in the industrial production of GAMG. [ABSTRACT FROM AUTHOR]

Chromosome segregation begins when the cysteine protease, separase, cleaves the Scc1 subunit of cohesin at the metaphase-to-anaphase transition. Separase is inhibited prior to metaphase by the tightly bound securin protein, which contains a pseudosubstrate motif that blocks the separase active site. To investigate separase substrate specificity and regulation, here we develop a system for producing recombinant, securin-free human separase. Using this enzyme, we identify an LPE motif on the Scc1 substrate that is distinct from the cleavage site and is required for rapid and specific substrate cleavage. Securin also contains a conserved LPE motif, and we provide evidence that this sequence blocks separase engagement of the Scc1 LPE motif. Our results suggest that rapid cohesin cleavage by separase requires a substrate docking interaction outside the active site. This interaction is blocked by securin, providing a second mechanism by which securin inhibits cohesin cleavage. Prior to anaphase, securin binds separase and thereby prevents cohesin cleavage. Here, the authors develop a method to produce active securin-free separase, identify a docking motif in cohesin that promotes cleavage, and show that securin interferes with this interaction. [ABSTRACT FROM AUTHOR]

Aim: Pseudomonas orientalis and Chaetomium cupreum isolated from metal(oid)s-contaminated soil were characterized to evaluate their role in plant growth promotion and enhance the tolerance of Eucalyptus globulus to copper stress.Methods: We evaluated minimum inhibitory concentration and explored plant-promoting traits under copper stress. Moreover, changes in morphology and the accumulation of metals on the cell surface were determined by scanning electron microscopy images coupled with energy dispersive x-ray spectroscopy (SEM-EDX). The effect of inoculation with P. orientalis and C. cupreum on E. globulus plants established in soils contaminated with copper was determined through root and shoot biomass and antioxidant response.Results: Both strains showed high tolerance to metal(oid)s, whereas phosphate solubilization was only detected in P. orientalis. Under copper stress, C. cupreum presented a higher production rate of siderophores and indole acetic acid (4.5 mm day−1, 15.042 μg mL−1). SEM images and EDX analysis reflected cellular changes in fungus and proved biosorption of copper. Inoculation of P. orientalis and C. cupreum on Eucalyptus globulus plants significantly increased plant growth and mitigated the toxic effects of copper.Conclusions: According to these results, both microorganisms contribute positively to stimulated plant growth and to decreasing stress caused by high concentrations of copper in soil, especially C. cupreum. [ABSTRACT FROM AUTHOR]

Fraction B was chromatographed on silica gel column with a gradient of ethyl acetate in petroleum ether (1:0, 50:1, 25:1) to give three subfractions (subfrs. The ethyl acetate extract was subjected to silica gel column chromatography eluting successively with dichloromethane-methanol gradient (50:1-0:1) to yield five fractions (A-E). Subfraction C2 was chromatographed over a silica gel column eluting with petroleum ether-ethyl acetate and then PTLC to afford compounds B 4 b (4.4 mg) and B 5 b (6.7 mg). [Extracted from the article]

Objective: We aimed to identify new high-yield dextranase strains and study the catalytic potential of dextranase from the strain in industrial applications.Results: Dextranase-producing strains were screened from soil samples, and a potential strain was identified as Chaetomium globosum according to its phenotype, biochemical characteristics, and rDNA analysis. Crude dextranase was purified to reach 10.97-fold specific activity and 18.7% recovery. The molecular weight of the enzyme was 53 kDa with an optimum temperature and pH of 60 °C and 5.5, respectively. Enzyme activity was stable at pH 4.0-7.0 and displayed sufficient thermal stability at temperatures < 50 °C. Mn2+ (10 mM) enhanced dextranase activity by 134.44%. The enzyme was identified as an endodextranase. It displayed very high hydrolytic affinity toward high-molecular weight dextran T2000, reaching 97.9% hydrolysis within 15 min at 2 U/mL.Conclusion: Collectively, these results suggest that Chaetomium globosum shows higher production and specificity of dextranase than that from other reported strains. These findings may offer new insights into the potential of dextranase in the sugar, medical, and food industries.Graphical abstract: [ABSTRACT FROM AUTHOR]

Nucleocytoplasmic transport occurs through nuclear pore complexes (NPCs), which are formed from multiple copies of ~30 different nucleoporins (Nups) and inserted into the double nuclear membrane. Many of these Nups are organized into subcomplexes, of which the Y-shaped Nup84 complex is the major constituent of the nuclear and cytoplasmic rings. The Nup82–Nup159–Nsp1 complex is another module that, however, is only assembled into the cytoplasmic ring. By means of crosslinking mass spectrometry, biochemical reconstitution, and molecular modeling, we identified a short linear motif in the unstructured N-terminal region of Chaetomium thermophilum Nup145C, a subunit of the Y-complex, that is sufficient to recruit the Nup82 complex, but only in its assembled state. This finding points to a more general mechanism that short linear motifs in structural Nups can act as sensors to cooperatively connect pre-assembled NPC modules, thereby facilitating the formation and regulation of the higher-order NPC assembly. [ABSTRACT FROM AUTHOR]

A novel fungal laccase produced by the ascomycete Chaetomium sp. isolated from arid soil was purified and characterized and its ability to remove dyes was determined. Extracellular laccase was purified 15-fold from the crude culture to homogeneity with an overall yield of 50% using ultrafiltration and anion-exchange chromatography. The purified enzyme was found to be a monomeric protein with a molecular mass of 68 kDa, estimated by SDS-PAGE, and with an isoelectric point of 5.5. The optimal temperature and pH value for laccase activity toward 2,6-DMP were 60 °C and 3.0, respectively. It was stable at temperatures below 50 °C and at alkaline conditions. Kinetic study showed that this laccase showed higher affinity on ABTS than on 2,6-DMP. Its activity was enhanced by the presence of several metal ions such as Mg, Ca and Zn, while it was strongly inhibited by Fe, Ag and Hg. The novel laccase also showed high, remarkable sodium chloride tolerance. Its ability to decolorize different dyes, with or without HBT (1-hydroxy-benzotriazole), as redox mediator, suggests that this protein may be useful for different industrial applications and/or bioremediation processes. [ABSTRACT FROM AUTHOR]

Fungal endophytes are group of fungi that grow within the plant tissues without causing immediate signs of disease and are abundant and diverse producers of bioactive secondary metabolites. The Chaetomium genus of kingdom fungi is considered to be a rich source of unique bioactive metabolites. These metabolites belong to chemically diverse classes, i.e., chaetoglobosins, xanthones, anthraquinones, chromones, depsidones, terpenoids and steroids. Cheatomium through production of diverse metabolites can be considered as a potential source of antitumor, cytotoxic, antimalarial, antibiotic and enzyme inhibitory lead molecules for drug discovery. This review covers isolation of Cheatomium endophytes, extraction and isolation of metabolites and their biological activities. [ABSTRACT FROM AUTHOR]

Members of the family Chaetomiaceae are ubiquitous ascosporulating fungi commonly, which reside in soil enriched with manure or cellulosic materials. Their role as human pathogens is largely ignored. However, the ability of some species to grow at high temperature enables them to play an important role as opportunistic pathogens. The family contains several genera and species that have never been reported to cause human infection. Hereby, three new species are described; two belong to the genus Subramaniula and one represents a Chaetomium species. Subramaniula asteroides was isolated from various sources including eye and skin infections as well as from the natural environment, and S. obscura was isolated from a toe infection. Chaetomium anamorphosum was isolated from a kidney transplant patient suffering from fungal peritonitis. All species described were previously misidentified as Papulaspora spp. due to the formation of cellular clumps or bulbil-like structures, which are characteristic of Papulaspora. The isolates failed to form sexual fruit bodies and ascospores remained absent, which is an unusual feature for the generally ascosporulating genera Chaetomium and Subramaniula; minute conidia from phialides were sometimes observed. [ABSTRACT FROM AUTHOR]

Nuclear pore complexes (NPCs) mediate transport between the nucleus and cytoplasm. NPCs are composed of ∼30 nucleoporins (Nups), most of which are organized in stable subcomplexes. How these modules are interconnected within the large NPC framework has been unknown. Here we show a mechanism of how supercomplexes can form between NPC modules. The Nup192 inner-pore-ring complex serves as a seed to which the Nup82 outer-ring complex and Nsp1 channel complex are tethered. The linkage between these subcomplexes is generated by short sequences within linker Nups. The conserved Nup145N is the most versatile connector of NPC modules because it has three discrete binding sites for Nup192, Nup170 and Nup82. We assembled a large part of a Chaetomium thermophilum NPC protomer in vitro, providing a step forward toward the reconstitution of the entire NPC. [ABSTRACT FROM AUTHOR]

Antioxidants have recently become the topic of interest as radical scavengers, which inhibit lipid peroxidation and other free radical mediated processes. Chaetomium madrasense AUMC 9376 was isolated from Cairo soil and evaluated for antioxidant activity by various assays, such as DPPH, reducing power, scavenging activity by ferrous ion, nitric oxide (NO) and total phenolic content. Different physical and chemical conditions of the production medium were optimized for enhancement of antioxidant activity. The results revealed that incubation for 15 days at 25 °C and pH 6 was the most favorable for antioxidant activity. Moreover, both glucose and sodium nitrate were the proper carbon and nitrogen sources, respectively for the highest antioxidant activity. The extraction of the broth culture filtrate with different solvents revealed that ethyl acetate extract possesses the highest antioxidant activity. The obtained results suggest that the experimental fungus has the potentiality as a source of strong natural and safe antioxidants safe for application in the food and cosmetics industries. [ABSTRACT FROM AUTHOR]

In 2020, I Arachis hypogaea i grown in a greenhouse showed leaf lesions and a 20% disease incidence rate. A pathogenicity test was conducted using 10, 2-week-old seedlings by spraying leaves with an aqueous ascospore suspension (10 SP 6 sp spore mL SP -1 sp ), and control plants were sprayed with water. Leaf lesions began as chlorotic lesions near the margins and progressed to necrotic lesions with chlorotic halos. [Extracted from the article]

Bifunctional catalase-peroxidases (KatGs) are heme oxidoreductases widely spread among bacteria, archaea and among lower eukaryotes. In fungi, two KatG groups with different localization have evolved, intracellular (KatG1) and extracellular (KatG2) proteins. Here, the cloning, expression analysis and subcellular localization of two novel katG1 genes from the soil fungi Chaetomium globosum and Chaetomium cochliodes are reported. Whereas, the metalloenzyme from Ch. globosum is expressed constitutively, Ch. cochliodes KatG1 reveals a slight increase in expression after induction of oxidative stress by cadmium ions and hydrogen peroxide. The intronless open reading frames of both Sordariomycetes katG1 genes as well as of almost all fungal katG1s possess two peroxisomal targeting signals (PTS1 and PTS2). Peroxisomal localization of intracellular eukaryotic catalase-peroxidases was verified by organelle separation and immunofluorescence microscopy. Co-localization with the peroxisomal enzyme 3-ketoacyl-CoA-thiolase was demonstrated for KatGs from Magnaporthe grisea, Chaetomium globosum and Chaetomium cochliodes. The physiological role of fungal catalase-peroxidases is discussed. [ABSTRACT FROM AUTHOR]

Cellulases can be engineered with enhanced properties for broad use in scientific and industrial applications. In this study, the wild-type cbh2 gene of the thermophilic fungus Chaetomium thermophilum encoding cellobiohydrolase II (CBHII) was mutagenized through in vitro directed evolution. The resulting Pichia pastoris yeast library was screened, and two transformants were selected for enhanced CBHII activities that were not attributed to increased gene copy numbers. The optimum fermentation times of the two mutant transformants were shortened to 4-5 days after methanol induction compared to 6 days for the wild-type. The optimum reaction temperature (60 °C) and pH level (5 or 6) of the mutant CBHII proteins, designated CBHIIX16 and CBHIIX305, were higher than those of wild-type CBHII (50 °C and pH 4). Kept at 80 °C for 1 h, CBHIIX16 and CBHIIX305 retained >50% of their activities, while the wild-type CBHII lost all activity. Sequence analysis of CBHIIX16 and CBHIIX305 revealed that they contained five and six mutated amino acids, respectively. Structural modeling confirmed the presence of carbohydrate binding type-1 and catalytic domains, where the hydrogen bond numbers between the 227th and 203rd amino acids were increased, which perhaps contributed to the elevated enzyme stability. Therefore, the two CBHII mutants selected for increased enzymatic activities also demonstrated elevated optimum reaction temperature and pH levels and enhanced thermal stability. These properties may be beneficial in practical applications for CBHII. [ABSTRACT FROM AUTHOR]

Chaetomium is a fungus species that inhabits different cellulose substrates. Some species of this genus destroy books, textile, and wood. This genus is of particular interest due to its antagonistic and enzyme peculiarities. Studies on morphological and cultural features of Chaetomium species have both theoretical and practical output. Growth rates and development of C. globosum, C. funicola, C. elatum, and C. spirale were studied under different temperatures (17-20°C, 25°C, 27°C, 30°C, and 33-35°C) and carbon source media (glucose, saccharose, mannite, lactose, amylum, and cellulose). The optimal growth temperature was 25-27°C for all the studied species, while the temperature range of 33-35°C inhibited the colonies' growth. Growth dynamics and colony shape and morphology, as well as development of overhead mycelium and ascocarps, varied greatly in different Chaetomium species in regard to the carbon source media. When comparing the destructive effect of four studied species and C. murorum on craft paper, the highest activity was registered for C. globosum, C. funicola, and C. elatum. [ABSTRACT FROM AUTHOR]

Dothediomycetes sp., Alternaria tenuissima, Thielavia subthermophila, Alternaria sp., Nigrospora oryzae, Colletotrichum truncatum, and Chaetomium sp. were isolated as endophytic fungi from leaves and stems of the medicinal plant, Tylophora indica, based on rDNA sequencing of ITS region and microscopic examination . Alternaria tenuissima, Colletotrichum truncatum, and Alternaria sp. were found to be active against both Sclerotinia sclerotiorum and Fusarium oxysporum. Chaetomium sp. showed very mild activity against Sclerotinia sclerotiorum and Fusarium oxysporum. Whereas Dothideomycete sp. and Thielavia subthermophila showed high activity against Sclerotinia sclerotiorum. Methanol extract of Dothediomycetes sp. showed 66.5% growth inhibition (GI) at 500 μg/ml. [ABSTRACT FROM AUTHOR]

Fifty-two endophytic fungi strains with different colony morphologies were isolated from stems, leaves and roots of Huperzia serrata (Thunb. ex Murray) Trevis. collected from Bawangling Reserve of Hainan Province in southern China. They were identified mainly based on rDNA ITS sequences and phylogenetic analysis. The results showed that all strains belonged to four classes, i.e. Sordariomycetes (92.31%), Dothideomycetes (3.85%), Pezizomycetes (1.92%) and Agaricomycetes (1.92%). Forty-seven strains were identified at the genus level, including Glomerella ( Colletotrichum), Hypocrea ( Trichoderma), Pleurostoma, Chaetomium, Coniochaeta ( Lecythophora), Daldinia, Xylaria, Hypoxylon, Nodulisporium, Cazia and Phellinus. As to the other five strains, three were identified at the order level and two at the family level, indicating that a great diversity of fungi taxa exists in H. serrata. Most isolated strains belonged to the genus of Glomerella ( Colletotrichum) and Hypoxylon, twenty-one from Glomerella and its anamorph Colletotrichum (42.3% of total isolated strains) and ten from Hypoxylon (19.2% of total isolated strains). Pleurostoma, Chaetomium, Coniochaeta ( Lecythophora), Daldinia, Xylaria, Hypoxylon, Nodulisporium, Cazia and Phellinus were reported as endophytic fungi isolated from H. serrata for the first time. [ABSTRACT FROM AUTHOR]

Nine 10-(indol-3-yl)-[13]cytochalasans such as a new chaetoglobosin V ( 1); two new natural products, prochaetoglobosin III ( 2) and prochaetoglobosin III ( 3); six known chaetoglobosins B-D ( 4–6), F ( 7), and G ( 8) and isochaetoglobosin D ( 9) in addition to two known sterols, 24( R)-5α,8α-epidioxyergosta-6–22-diene-3β-ol ( 10) and ergosterol ( 11), were isolated from the fungus Chaetomium elatum ChE01. The structures of these compounds were elucidated by spectroscopic methods. Compounds 1–9 showed cytotoxicity against the human breast cancer (IC 2.54–21.29 μM) and cholangiocarcinoma cell lines (IC 3.41–86.95 μM). [ABSTRACT FROM AUTHOR]

Thermophilic organisms produce thermostable enzymes, which have a number of applications, justifying the interest in the isolation of new thermophilic strains and study of their enzymes. Thirty-four thermophilic and thermotolerant fungal strains were isolated from soil, organic compost, and an industrial waste pile based on their ability to grow at 45°C and in a liquid medium containing pectin as the only carbon source. Among these fungi, 50% were identified at the genus level as Thermomyces, Aspergillus, Monascus, Chaetomium, Neosartoria, Scopulariopsis, and Thermomucor. All isolated strains produced pectinase during solid-state fermentation (SSF). The highest polygalacturonase (PG) activity was obtained in the culture medium of thermophilic strain N31 identified as Thermomucor indicae-seudaticae. Under SSF conditions on media containing a mixture of wheat bran and orange bagasse (1 : 1) at 70% of initial moisture, this fungus produced the maximum of 120 U/ml of exo-PG, while in submerged fermentation (SmF) it produced 13.6 U/ml. The crude PG from SmF was more thermostable than that from SSF and exhibited higher stability in acidic pH. [ABSTRACT FROM AUTHOR]

A gene encoding a novel chitinase chi58 was cloned from the fungus Chaetomium cupreum by using inverse PCR. The DNA sequence of chi58 contains a 1,602 bp open reading frame and two introns that are 52 and 201 bp in length. Regarding our in silico analysis, chi58 is a modular enzyme composed of a family-18 catalytic domain, which is responsible for chitinase activity, and a chitin-binding domain containing several cysteines. Apparently, the function of these domains is to anchor the enzyme tightly onto the large insoluble polymeric substrate. Chi58 has a pI of 4.47 and a deduced molecular mass of 58 kDa. The optimal pH and temperature conditions were determined to be 5.8 and 45°C, respectively, when colloidal chitin was used as the substrate. SDS-PAGE and zymogram analyses indicated the presence of a single active chitinase. Cells with pPIC9K -chi58 produced an extracellular chitinase that had an activity of 39 U/ml protein. Metal ions such as Ba2+, Mg2+, K+, Cu2+, Fe3+, Zn2+, and Co2+ also influenced the activity of the recombinant enzyme. [ABSTRACT FROM AUTHOR]

Three endoxylanase genes were cloned from the thermophilic fungus Chaetomium thermophilum CBS 730.95. All genes contained the typical consensus sequence of family 11 glycoside hydrolases. Genomic copies of Ct xyn11A, Ct xyn11B, and Ct xyn11C were expressed in the filamentous fungus T. reesei under the control of the strong T. reesei cel7A (cellobiohydrolase 1, cbh1) promoter. The molecular masses of the Ct Xyn11A, Ct Xyn11B, and Ct Xyn11C proteins on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were 27, 23, and 22 kDa, respectively. Ct Xyn11A was produced almost as efficiently as the homologous xylanase II from a corresponding single-copy transformant strain. Ct Xyn11B production level was approximately half of that of Ct Xyn11A. The amount of Ct Xyn11C was remarkably lower. Ct Xyn11A had the highest temperature optimum and stability of the recombinant xylanases and the highest activity at acid-neutral pH (pH 5–7). It was the most suitable for industrial bleaching of kraft pulp at high temperature. [ABSTRACT FROM AUTHOR]

Chaetomium cupreum has a potential as biocontrol agent against a range of plant pathogens on the basis of production of antifungal metabolites, mycoparasitism, competition for space and nutrients, or various combinations of these. To explore genes expressed in C. cupreum, a cDNA library was constructed from mycelium and 3,066 expressed sequence tags (ESTs) were generated. Clusters analysis enabled the identification of 1,471 unigenes with 392 contigs and 1,079 singleton sequences. Putative functions were assigned to 874 unigenes that exhibited strong similarity to genes/ESTs in public databases putatively containing genes involved in cellular component, molecular function, and biological process. Other 597 ESTs representing novel genes showed no significant similarity to public database resource of NCBI. A proportion of genes was identified related to degradation of pathogen cell wall, antifungal metabolite production, as was estimated in the biocontrol fungus. The paper described is a first step towards the knowledge of the C. cupreum genome. The results present the useful application of EST analysis on C. cupreum and provide a preliminary indication of gene expression putatively involved in biocontrol. [ABSTRACT FROM AUTHOR]